Chance seedlings of both the Persian and Eastern black walnut are also being evaluated 

 for hardiness and other desired traits. 



As selections and varieties are evaluated and found superior to standard varieties they will 

 be named and introduced. In evaluation studies at Beltsville, Md., the Hansen variety of 

 Persian walnut continues to be outstanding from the standpoint of production, winter-hardi- 

 ness, and quality. It is being widely planted as a dooryard and utility tree. 



Filberts 



More winter hardy varieties of filberts are being sought by ARS researchers at Corvallis, 

 Oreg., and Beltsville, Md., for growing in the Pacific Northwest and the Northeast. 



Neither of the established European varieties grown in the Pacific Northwest (Barcelona 

 in Oregon and DuChilly in Washington) is reliably winter hardy in commercial plantings. In 

 fact, all existing commercial varieties mature so late in Washington and Oregon that in some 

 years a high percentage of the crop is lost. 



To help overcome this hazard, crosses between Barcelona and other western varieties 

 have been made, selections from superior progeny backcrossed, and several promising selec- 

 tions from later generations of the same parentage chosen on the basis of early maturity and 

 disease resistance. ^ 



Since the American filbert is winter hardy, it is currently being crossed with English 

 varieties to produce hybrids combining hardiness with desired qualities of the Barcelona and 

 other European filberts. Two of these hybrids, which were propagated by the Department 

 and introduced in 1951 as the varieties Reed and Potomac, are being widely planted in Eastern 

 and Northern areas where filberts have not been grown before. 



In a long-term breeding project at Beltsville, Md., selections showing superior winter 

 hardiness potential have been chosen from second generation progeny of various crosses. 



Chestnut 



With the destruction of native chestnut forests by the chestnut blight, the need for blight 

 resistant varieties which are hardy enough to grow throughout the range for American chest- 

 nuts has increased. 



To meet this need, USDA scientists are actively working to develop by means of selection 

 and hybridization varieties that combine these characteristics with other desired traits such 

 as resistance to attack by weevils. 



As Japanese and Chinese chestnuts are more resistant to the blight than American or 

 European varieties, breeding work has been largely confined to selections or hybrids of oriental 

 varieties. At present the Chinese chestnut appears to offer the greatest promise for improve- 

 ment by breeding. However, Chinese varieties characteristically have some defects such as 

 liability to attack by weevils and some susceptibility to blight. Also, the young trees are very 

 subject to winter injury although mature Chinese chestnuts are generally hardy in areas where 

 the American chestnut succeeds. 



Tung 



Hardiness is a major objective in tung improvement research by ARS and cooperating 

 States. 



The early blooming habit of the tung species (Aleurites jordii) grown in this country 

 constitutes a serious hazard in the commercial production of this subtropical oil crop in the 



